Elevation in cardiovascular disease risk in South Asians is mediated by differences in visceral adipose tissue.

TitleElevation in cardiovascular disease risk in South Asians is mediated by differences in visceral adipose tissue.
Publication TypeJournal Article
Year of Publication2012
AuthorsLear, SA, Chockalingam, A, Kohli, S, Richardson, CG, Humphries, KH
JournalObesity (Silver Spring)
Volume20
Issue6
Pagination1293-300
Date Published2012 Jun
ISSN1930-739X
KeywordsAbsorptiometry, Photon, Asian Continental Ancestry Group, Blood Glucose, Body Composition, Body Mass Index, Cardiovascular Diseases, Cholesterol, HDL, Cohort Studies, Diabetes Mellitus, Type 2, European Continental Ancestry Group, Female, Genotype, Humans, Intra-Abdominal Fat, Lipids, Male, Middle Aged, Obesity, Phenotype, Risk Factors, Social Class, Subcutaneous Fat, Abdominal, Triglycerides
Abstract

South Asians have a higher risk for cardiovascular disease (CVD) that remains largely unexplained. We hypothesized that the increased CVD risk in South Asians compared to Europeans is mediated through higher levels of visceral adipose tissue (VAT) in South Asians compared to total body fat and subcutaneous abdominal adipose tissue (SAT). South Asians (207) and Europeans (201) underwent assessment for demographics, body fat, and risk factors. Linear regression models were created by sex for each risk factor to explore mediation effects of total body fat, SAT, and VAT adjusted for age, income, smoking, and BMI (menopausal status for women). Mediation was based on changes in the ethnicity β coefficient due to additional adjustment for our adipose variable of interest and the Sobel test for mediation. South Asians had worse lipid, glucose, insulin, and C-reactive protein (CRP) levels than Europeans after adjusting for confounders. Most of these differences remained even after further adjustment by either total body fat or SAT. In contrast, VAT attenuated the ethnic differences in risk factors by 16%-52%. After adjusting for VAT, there were no longer ethnic differences in total cholesterol (TC), LDL-C, TC/HDL-C, glucose, and diastolic blood pressure (BP) in men, and in HDL-C, triglycerides (TG), TC/HDL-C, and homeostasis model (HOMA) in women, and VAT was a significant mediator for these risk factors. Higher levels of risk factors for CVD in South Asians are predominantly because of the unique phenotype of South Asians having greater VAT than Europeans even at the same BMI.

DOI10.1038/oby.2011.395
Alternate JournalObesity (Silver Spring)
PubMed ID22282045
Grant List / / Canadian Institutes of Health Research / Canada